Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!

Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.

Did you check your compression with throttle wide open and at operating temperature? With all plugs out and fuel discharged? Lack of compression in CYL 3 could suggest a connecting rod bearing letting loose creating lower compression numbers compared to other cylinders.

~Now that you verified compression is within spec keep in mind the elevation you are at, do a leak-down test and see what happens.

I did have an EJ25D make a similar noise however it was more consistent through the rev range ~Turned out someone timed it a few teeth out.

Could be timing. I've done compression test and there all very close to eachother. The motor was replaced and I don't think it was driven since it was replaced.
I'm gonna put thicker oil In it and run it so more and see if anything changes.
Then ill either check timing or pull the could And see what cylinder is really making the noise. I'm 99% sure it's the 3rd cylinder